Refrigerating apparatus



Oct. 18, 1955 L. A. PHlLlPP 2,720,759

REFRIGERATING APPARATUS Filed April 14, 1953 INVENTOR. 5/

fives/v05 H. PHILIP? United States Patent O M REFRIGERATIN G APPARATUS Lawrence A. Philipp, Detroit, Mich, assignor to Nash- Kelvinator Corporation, Detroit, Mich, a corporation of Maryland Application April 14, 1953, Serial N 348,615

4 Claims. (Ci. 62-103) This invention relates to refrigerating apparatus and more particularly to defrosting said apparatus and the entire liquification of the frost and ice removed therefrom.

It is an object of my invention to provide a refrigerator divided into two compartments by a drip bafiie immediately below the evaporator to collect drip water from the evaporator during defrost thereof and to provide an improved arrangement for heating the drip water, frost, and ice which leaves the evaporator during defrosting thereof so that same will not freeze upon coming into contact with the drip baflie.

Another object of the invention is to provide for a refrigerator having a freezing compartment separated from a food storage compartment by a readily removable separator, an improved arrangement for heating the drip water without interference of readiy removability of the separator.

Other objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. l is a fragmentary front view of a household refrigerator embodying features of my invention and showing portions thereof broken away; and

Fig. 2 is a diagrammatic illustration of the refrigerator system embodying features of my invention.

Referring to the drawing by characters of reference, the numeral 29 designates generally a refrigerator cabinet of the household type having the usual front access opening, closable by a door 22. A refrigerant evaporator 24 is disposed within the cabinet 29 adjacent the top thereof, and directly below the evaporator is a separator or horizontal partition 26 which divides the cabinet into an upper freezing compartment 28 and a lower food storage compartment 39. The separator 26 has its edges spaced from the cabinet walls to provide for limited air circulation between the compartments to efiect cooling of the food storage compartment 30 by the evaporator 24. Also, the separator 26 functions as a drip pan baffle during defrosting of the evaporator 24 and is made readily removable from the cabinet for easy cleaning by slidably supporting the baflie on guide rails 34 which may be secured to oppo site inner sides of the cabinet. Within the food storage compartment 30, a number of vertically spaced shelves 36 may be provided, and a removable drip container 38 may be supported on the uppermost of the shelves 36 to receive drip water from the separator 26.

Any suitable type of evaporator may be used, the present evaporator 24 being of the direct expansion or so-called dry type and comprising generally a box-like container 40 and a refrigerant coil 42. Preferably the container 40 extends substantially to the cabinet side and rear walls and to door 22 to provide large freezer storage capacity. The front of the container 49 has an 2,720,759 Patented Oct. 18, 1955 access opening which is closable by a door 44. As is well known, the container 40 forms extended heat absorbing surfaces for coil 42 which is wound about the top, bottom, and sides of the container 40 and may be secured thereto, such as by brazing, to obtain efiicient conduction of heat between the coil and container. The inlet end of the evaporator coil 42 is connected to a refrigerant receiver 46, preferably to the top thereof, and the outlet end of coil 42 is connected to a refrigerant accumulator 48 which is secured to the rear wall of the container 40.

The refrigerating system includes a refrigerant motorcompressor unit 50 and a refrigerant condenser 52. A conduit 54 connects the outlet of the motor-compressor unit 50 to the condenser 52, and the outlet of the condenser 52 is connected to the receiver 46 by a small diameter conduit or capillary tube 56 which preferably connects to the receiver 46 at the top thereof or adjacent the inlet of the evaporator coil 42. A suction line or return conduit 58 connects the accumulator 48 to the intake of the motor-compressor unit 50. The motor-compressor unit may be of any of the well known units having a motor and a compressor enclosed in a sealed casing, such as the unit shown in my Patent No. 2,199,415, dated May 7, 1940.

Preferably the separator 26 is made in two sections of a low heat conducting material such as plastic material and includes an upper pan section 60 and a lower pan section 62. The upper pan section 60 fits into the lower and may be cemented or be otherwise secured thereto. Heat insulation 64 is preferably provided between the pan sections to reduce transfer of heat between the freezing and food storage compartments. As shown, the upper pan section 60 is inclined downwardly to the rear edge thereof where a drain trough has a drain 66 which discharges into the drip container 38.

A defrosting system for the evaporator 24 is provided and includes a conduit 70 and the receiver 46. The conduit 70 connects the motor-compressor discharge conduit 54 to the receiver 46 and therefore to the evaporator 24 to bypass the condenser 52. On defrosting operation of the evaporator 24, relatively warm gaseous refrigerant is conducted from the motor-compressor unit 50 through the by-pass conduit 70 into the receiver 46, and then through the evaporator 24, back to the motor-compressor unit 50, and circulation of the refrigerant is continued until defrosting of the evaporator 24 is completed. A normally closed solenoid valve 72 controls flow through the by-pass conduit 70. In order to insure passage of the gaseous refrigerant through bypass conduit 70 on the defrosting operation, the conduit is provided with a larger internal diameter than the inlet to the capillary 56, thus present ing the path of lesser flow resistance.

The receiver 46 is kept completely filled with liquid refrigerant by the capillary tube 56 which functions during the normal refrigerating operation to meter and supply just sufficient refrigerant to the evaporator 24 to keep the same refrigerated to the desired temperature. As refrigerant is forced from the capillary tube 56 into the completely filled receiver 46 by the action of the compressor, refrigerant in the receiver is displaced into the evaporator 24. The function of the receiver 46 is to contain a body of liquid refrigerant for supplementing on defrosting operation, the refrigerant normally used for refrigeration whereby to decrease the interval of defrosting the evaporator. On defrosting operation, the liquid refrigerant in the receiver 46 is subjected to higher pressure and is forced through the evaporator into the suction line 58 and into the motor-com pressor casing where it is evaporated by the heat of the motor and compressor.

quick defrost system or any ice dropping fror n'th'e evaporator 24 would ordinarily build up on the cold separtitbr 26 and so to avoid this I p qy e f r int rc pt aathe ip wat f os nd ice by mean? of a hea e baf e Eu then, I rra g the hea ed ba ie 7 spare e a io to an a v he. sep ra slti o. ha h re is. o nte ence with r a y cmoyab l ty 9 he parat The atfle '1 q mprise sh me a p ate 6 P efe ably o i h he t c nd cta mater a as a st a d his p a iste in he. detm t ng period y he ho as refr t fl nst hrou h. he bi -P s condu 70- As ho n, a per iQn 78 of. e a dul s ecu e n g d eat transfe relationship to the underside of the baffie plate 76 so at. w en the def o ing sys em. op ates, e Pl te 76 will be heatedand the drip water, frost particles, a d s: hunk n ercep ed therebyw ll be melted n he resultant water drained to receptacle 38 instead of ice and os u ld up n the s para o 2 T bafiie plate 76, is inclined from front to rear thereof to drain water therefrom into the trough of the separator 26 for drainage into the removable drip container 38,

Inthe present refrigerator, the defrosting operation is controlled by the solenoid. 72 in the bypass line 70,

7 and the solenoid is in turn controlled by a pushbutton starter ,switch- 82 and by a thermostat 84. The switch 82 is of the overcenter or snap type and is pushed to engage a pair of contacts 86 to close the circuit of the solenoid. '72 thus to initiate defrosting operation of the evaporator 24. The motor of unit 50 is connected by lead wires 90 and 92 to main leads 94 and 96, and in motor lead wire 92 is a switch 98 of the thermostat 84, A lead wire 100, connects one of the push button contacts 86 to the coil of solenoid 7 2,.and the other end of the solenoid coil is connected to mainlead; wire 96,

by a lead wire 102. A lead wire 104 connects the push button contact 86 to main lead 94.

The thermostat 84 includes a pressure responsive. bellows 10.6 and feeler bulb 108 which are charged with an expansibleacontractible fluid responsive to the temperature of evaporator 40 to actuate switch 98. The

84 to maintain the .desired evaporator temperature When the temperature of the evaporator 24 rises such that the thermostat 84 closes switch 98, the motor-com-.

pressor unit; 50 operates and delivers gaseous refrigerant to the condenser whence liquid refrigerant is conducted through the capillary tube 56' to the receiver 46. The high side pressure forces liquid refrigerant out of the completely filled. receiver 46 through the evaporator 24, and through. suction line 58 to the motor-compressor unit. This cycle is repeated until the temperature of the evaporator 24 is decreased such that the thermostat 84 opens the control switch 98. of themotor-compressor unit 50.

- To initiate defrosting of theevaporator 24, switch button 82 ispushedand moves overcenter'to engage contacts 86, provided, of course, that the evaporator temperature issufliciently lowsu'ch that thermostat rod llfldoes not interferewith the push button. Qn closing of switch con-. tacts 8.6,, the circuit ofthe coil of the normally closed solenoid. 72 is completed andv the solenoid is energized and opens to permit flow through conduit 70 of gaseous refrigerant from the motor-compressor unit and at thesametime interrupts the refrigeration operation since the,

gas takesthe larger path of lesserresistance or conduit 70. On opening of-the solenoid 72, the high backpressure of the high side is diverted throughby-pass conduit'70 and this high pressure drives all of the liquid refrigerant out of the receiver 46 into the evaporator 24. By this means, the quantity of refrigerant for use as a heat transference medium is increased with accompanying decrease in the interval necessary for defrosting the evaporator 24. The gaseous refrigerant entering the evaporator 24 condenses in the cold region and gives up its heat to raise rapidly the temperature of the evaporator.

The liquid refrigerant from the receiver 46 passes through the evaporator 24 and is conducted through'return conduit 58 to the motor-compressor unit 50, which evaporates the refrigerant to increase the vapor pressure in the evaporator 24 due to the latent heat of eyaporation. On entering the unit 50, the refrigerant is evapor ated by the heat generated by the unit, such as the heat of electrical losses and friction, and the resultant latent heat of vaporization is thus acquired to aid in rapidly defrosting the evaporator. The gaseous refrigerant condenses in the evaporator 24, giving up its heat thereto and returns to the motor-compressor 52 to be heated thereby and again carrying the heat to the evaporator, Circulation of hot refrigerant vapors continues until the evaporator 24 is completely defrosted, at which time the thermostat 84 pushes switch 82 to off position which deenergizes the solenoid 72 and returns the system to normal refrigerating operation. Switch blade, 98. is flexible to permit sufficient movement of the bellows 106 to open switch. 82 without disengaging the con-1 tacts of switch 98. By this arrangement the thermostat- 84 keeps the circuit of the compressor motor of unit. 50 closed so that the unit continues to operate to again.

bring the temperature of the evaporator down to the desired temperature or temperature for which the there mostat is set, For a further and more detailed description of the defrosting system reference may be had to my co-pending application on refrigerating apparatus, Serial No. 247,799, filed September 22 1951, now Patent No. 2,679,141 the present system being adapted to operate in the same manner as that disclosed in said. copending application, except for receiver 46.

Asvthe temperature of the evaporator 24. increases, Water, frost, and ice drop therefrom onto the heated baffle 76 which melts the frost and ice so that each defrosting period, all of the frost and ice is disposed of instead of building up on the baflie. In quick defrost systems of the present type, the defrost interval is so short that the compartment separator 26 does notwarm up sufficiently to melt frost and ice thereon and drip Water will refreeze on the cold separator and frost and ice build up thereon. between the separator 26 and the evaporator 24fnot only intercepts most of the chunks of ice, frost, and water that leave the evaporatoron defrost thereof, but melts the ice chunks and front and drains the resultant; water to the separator which is also heated due to the.

proximity of the warm by-pass'coil 76 on the: under; side of the bafiie 76 so that all frost particles and ice chunksare melted either on the battle 76 or on the separator;

26. The frost and ice melted on theflbaffle 76 andseparator 26 together with the drip water are drained: to the rear of the separator and then into the drip =eontainer- 38.

From the foregoing description it will now be under? stood that I have provided for refrigerator systems hav.-,

ing rapid defrosting systems, an arrangement for intercepting drip water, frost and ice between the evaporator and a compartment separator or partition so. that ice,

will not form on the cold separator. In addition, it will. be understood that by locating the heatedv drip baflie above and in spaced relation to the separator that the separator is free for ready removal from the cabinet for easy cleaning of the separator.

Although only a preferred form of the inventionhas been illustrated, and that form describedin detail, it Will However, my heated haffie 76 be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

l. Refrigerating apparatus comprising, a cabinet, a removable separator within said cabinet separating a freezing compartment and a cooling compartment from each other, said separator having a drain for disposal of defrost water, a refrigerant evaporator within said freezing compartment, said separator extending beneath said evaporator in spaced relation thereto and having edges spaced from the cabinet walls to permit limited air circulation between the cooling compartment and said evaporator, a baflle plate to intercept drip water and ice falling from said evaporator on defrosting of the evaporator, said baffle plate disposed between and spaced from both said evaporator and said separator and inclined to discharge defrost water onto said separator adjacent the drain thereof, and a heater interposed between said bafiie plate and separator in spaced relation to and above the latter and operable to heat both the bafiie plate and separator on defrosting of said evaporator.

2. Refrigerating apparatus comprising, a cabinet, a removable separator within said cabinet separating a freezing compartment and a cooling compartment from each other, said separator having a drain for disposal of defrost water, a refrigerant evaporator within said freezing compartment, said separator extending beneath said evaporator in spaced relation thereto and having edges spaced from the cabinet walls to permit limited air circulation between the cooling compartment and said evaporator, a baflie plate to intercept drip water and ice falling from said evaporator on defrosting of the evaporator, said baffle plate disposed between and spaced from both said evaporator and said separator and inclined to discharge defrost water onto said separator adjacent the drain thereof, a relatively hot refrigerant vapor conducting conduit leading from a refrigerant compressor to the evaporator having a sinuous portion secured in heat conducting relation to the underside of said baflie plate to oppose freezing of defrost water thereon.

3. Refrigerating apparatus comprising, a cabinet, a partition within said cabinet separating an upper freezing compartment and a lower cooling compartment from each other, said partition having a drain for disposal of defrost water, a refrigerant evaporator within said freezing compartment, said partition arranged in spaced relation to said evaporator and having edges spaced from walls of said cabinet for limited air circulation between the compartments, a baflle member between said evaporator and said partition spaced from both and discharging onto said partition, said bafiie member overlying substantially the entire area of said partition, and a relatively hot refrigerant vapor conduit leading from a refrigerant compressor having a sinuous portion disposed between said partition and said bafile closer to the latter to melt ice thereon and keep the defrost water fluid.

4. Refrigerating apparatus comprising, a cabinet, a removable partition separating a freezing compartment and a cooling compartment from each other, heat insulation within said partition, said partition having a drain for disposal of defrost water, a refrigerant evaporator within said freezing compartment, said partition extending beneath said evaporator in spaced relation thereto having edges spaced from walls of said cabinet for limited air circulation between the compartments, a baflle interposed between said evaporator and partition in spaced relation thereto and arranged closer to said partition than to said evaporator, said baffle arranged to discharge defrost water onto said partition, a relatively hot refrigerant vapor conduit leading from a refrigerant compressor to said evaporator having a portion secured in heat conducting relation to the underside of said bafiie to oppose freezing of defrost water thereon.

References Cited in the file of this patent UNITED STATES PATENTS 2,199,415 Philipp May 7, 1940 2,440,146 Kramer Apr. 20, 1948 2,451,682 Lund Oct. 19, 1948 2,600,297 Janos June 10, 1952 2,635,439 Philipp Apr. 21, 1953 2,641,908 La Porte June 16, 1953 2,645,101 La Porte July 14, 1953 2,645,909 Philipp July 21, 1953 2,688,850 White Sept. 14, 1954 

